Conventional wheelchairs of the folding type normally incorporate crossing tubes pivoted together at their cross-over points so that they can be scissored towards a vertical position to collapse the left and right frame tube sides together. The wheelchair seat and back rest are made generally of flexible canvas-like material which will simply fold when the left and right frame portions are brought together.
In folded configuration, the overall width is determined by the spacing of the wheels, generally the rear wheels of the wheelchair. The folded seat frame portions and so forth are accommodated within this width, the overall structure being such that the spacing between the seat support frame tubes and arm rest support frame tubes is always less than the spacing between the wheels in both unfolded and folded positions of the wheelchair.
As an example, for a conventional wheelchair with standard arm rests having a 16-inch seat width, the overall width between the rear wheels is 225/8 inches. In the case of a normal wheelchair of standard arms having an 18-inch seat width, the overall width of the rear wheels is 245/8 inches. There are certain environments having very narrow doorways or hallways which simply cannot conveniently accommodate a wheelchair having such overall width dimensions as measured between the rear wheels. Further, when the chairs are folded, even in their folded position the overall width for a given seat width is of such dimension as to render it difficult to accommodate the folded wheelchair in trunks of automobiles, particularly compact automobiles.